The objective of this research is to examine the metabolism of estrogens and the role of various metabolites in the development of certain cancers. First, this research will focus on the possible formation of "reactive" intermediates in vitro and the irreversible binding of these metabolites to cellular macromolecules. Gel chromatography will be used to isolate irreversibly bound components and characterization of these components by mass spectrometry and NMR spectroscopy will follow. Secondly, studies will focus on the enzymatic processes involved in these metabolic transformations, with particular emphasis on estrogen 2-hydroxylase and uterine perioxidase. The kinetics of the enzymes and their substrate specificities will be determined. The in vitro and in vivo regulation of these enzymatic activites will be explored. Potential steriodal inhibitors, competitive and irreversible compounds, will be synthesized and evaluated in biochemical assays. In vivo induction by known P450 inducers and inhibition by metyrapone or beta-naphtoflavone will also be examined. Thus, this proposal will attempt to examine the question of estrogens and carcinogenesis from chemical and biochemical terms.